Trust is a social and psychological expectation that another person, group or institution will behave in a sufficiently reliable, competent or non harmful manner despite uncertainty and vulnerability. Trust involves accepting some degree of risk because the trusted party has the opportunity to behave in ways that affect the interests of the person who trusts them. It is therefore different from certainty. If behaviour were completely predictable and guaranteed, trust would be less conceptually important.
Trust can be directed toward individuals, organisations, institutions, professionals, technologies or social systems. Its basis can include previous experience, reputation, competence, shared values, formal safeguards, emotional attachment and perceived intentions. Trust is central to relationships because extensive monitoring of every interaction would be costly or practically impossible.
Trust can be cognitive, affective or institutional. Cognitive trust is based largely on evidence concerning competence, reliability and predictability. A person may trust a professional because they possess relevant expertise and a record of accurate performance. Affective trust develops through emotional bonds, care and the belief that another person is concerned about one's welfare. Institutional trust concerns confidence that an organisation or system will behave according to accepted standards, procedures and responsibilities.
These forms can overlap but should not be treated as identical. Someone may trust a doctor professionally while having little emotional relationship with them, while a person may feel strong affection for a friend without considering that friend reliable for technical advice. Distinguishing different bases of trust helps explain why trust can be strong in one domain and weak in another.
Trust is closely related to risk, uncertainty and vulnerability. To trust another person is to accept that their future behaviour cannot be completely controlled. People therefore use signals to estimate whether trust is justified. Such signals can include past behaviour, reputation, credentials, recommendations, institutional affiliation and observable competence. These signals are imperfect because people can misrepresent themselves or circumstances can change. Trust can consequently be calibrated rather than absolute.
Excessive trust can expose people to exploitation, while excessive distrust can prevent beneficial relationships and increase transaction costs. Rational trust does not require certainty that another person will never fail. It involves an assessment that reliance is sufficiently justified given available evidence, the consequences of failure and available safeguards.
Trust develops through experience and repeated interaction. When people consistently keep commitments, communicate honestly and respond appropriately to mistakes, others can update their expectations in a favourable direction. Violations can have disproportionate effects because they challenge assumptions that future behaviour will be reliable. The severity of a breach depends on its consequences, intentionality, frequency and the importance of the relationship. Trust repair may involve acknowledgement, explanation, apology, compensation, changed behaviour and institutional safeguards. Simply promising not to repeat a violation may be insufficient if the underlying mechanism that produced the breach remains unchanged. This is why rebuilding trust often requires observable evidence over time rather than verbal assurances alone.
Trust is important for economic and organisational activity because it reduces the need for constant monitoring and enforcement. Contracts, audits, regulations and formal procedures remain important, but trust can make relationships more flexible and less costly to manage. Employees who trust managers may communicate problems earlier, share information and accept organisational change more readily. Consumers rely on trust when purchasing products or services whose quality cannot be fully evaluated in advance.
Scientific communities depend on trust in research procedures, professional standards and reporting, although verification remains essential. Trust therefore does not mean abandoning scrutiny. In many settings, effective systems combine trust with accountability, transparency and independent checks. Such arrangements recognise that people can be generally trustworthy while still making errors or facing incentives that sometimes conflict with others' interests.
Trust can exist between people who share values and between people who differ significantly but rely on formal expectations. Personal trust is usually based on direct knowledge of another person, while institutional trust allows people to rely on strangers through shared rules and procedures. Modern societies depend heavily on this latter form because individuals routinely interact with people they have never met.
A person may trust a payment system, transport network, professional certification system or public institution without knowing the individuals operating it. Institutional trust can therefore be supported by transparency, competence, procedural fairness and consistent enforcement. When institutions behave unpredictably or appear to apply rules selectively, trust can decline even if individual officials remain personally trustworthy.
Trust and distrust are not simply opposites on a single scale. People can remain uncertain without actively distrusting someone, and they can trust one aspect of a relationship while distrusting another. Suspicion may arise from incomplete information without implying a settled judgement that another party is malicious. Researchers also distinguish between trustworthiness and trust. Trustworthiness concerns characteristics or behaviour that make reliance appropriate, whereas trust is the judgement or relationship formed by the trusting party.
A person may be trustworthy but not trusted because others lack information about them. Conversely, someone may be trusted despite behaving unreliably because others possess inaccurate information. This distinction is important when analysing trust failures because increasing trust without increasing actual reliability can make people more vulnerable rather than improving relationships.
Trust is closely connected to cooperation, reciprocity, social capital and Social Trust. Interpersonal trust can facilitate cooperation because people are more willing to depend on others when they expect reliable behaviour. Reciprocity can generate trust through repeated exchanges, while trust can make reciprocal cooperation easier to initiate. Social capital describes resources available through relationships and networks, and trust is often considered one component or mechanism within these broader social relationships.
Social Trust extends the concept beyond particular relationships to expectations about other people in society generally. Trust therefore operates at several levels, from intimate relationships to institutions and wider communities. Its consequences depend on the object of trust, the evidence supporting it, the level of vulnerability involved and the safeguards available if expectations are violated.
